Re: st: Keep/Drop Observations for Top/Bottom X%

You need not -keep- or -drop- to do this; in fact -keep- or -drop-
here is usually a bad idea.
(Furthermore, regressions of this kind are often more problematic than
they seem, but I'll let others expand on that if they wish.)
For full flexibility here, skip -summarize- and go straight to -_pctile-.
For example,
. sysuse auto
(1978 Automobile Data)
. _pctile mpg, p(10 90)
. ret li
scalars:
r(r1) = 14
r(r2) = 29
So you can follow up with
... if mpg >= 29
Warnings:
1. Watch out for ties.
2. Watch out for missing values at the top end.
... if mpg >= 29
would include missings on -mpg- (if there were any). -if inrange(mpg,
29, .)- excludes the missings.
Nick
On Thu, Oct 11, 2012 at 10:34 AM, Lisa Wang <lhwang0925@gmail.com> wrote:
> I am unsure as to how I would go about keeping or dropping the
> top/bottom X% of observations of a variable. I would like to do this
> for further analysis on a subset of my data. For instance, I want to
> do some further regressions for the top 10% of my observations based
> on 'distance from home' and not the whole data set.
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